1. Field of the Invention
This invention relates to a strain gauge type torque sensor for measuring precision values of torque generated as a function of fluid parameters existent within an environment separate from the strain gauge elements such as the hostile environment found in an oil or gas well. Specifically, oil or gas well environments often include exposures to such extreme fluid parameters as high temperature, high pressure, corrosive media, shock and vibration. Additional limitations, restrictions or requirements on or of a downhole sensor usually include a small diametrical size, low power consumption and the ability to make accurate measurements in the presence of all of these factors.
2. Description of Related Art
Torque is often measured by the utilization of strain gauges in various configurations. These types of measurement techniques, however, are generally limited to values of torque that are high enough to create measurable strain levels within a shaft or torsion element. Also, these configurations would normally only lend themselves to physical configurations that preclude routing of associated sensor wiring within a fluid media. These criteria are often not met when measurements are to be made below the surface, as in an oil or gas well. Additionally, torque output responses derived from physical measurements often require that the torque should be measured primarily as a force imposed upon a lever of known length rather than as a material displacement. It is an object of this invention, then, to provide a strain gauge type torque sensor, suitable for use with precision physical measurement devices which develop a torque parameter output within a hostile well environment.